Thanks all for the replies!
It seems like I really should use a timer then. I am going to build one like I referenced in that post. I was considering a WeMo (I had one a while back) but I really like the idea of a mechanical timer which won't suddenly behave differently if somehow the settings get changed (power surge, outage, or software update). That said, if I could get it it react to the amount of power draw, that might change the equation a bit. The amazon link (and stanley) timers also look interesting... I might try one of those instead.
Thanks again!